[PATCH 04/14] Allow CONFIG_MIGRATION to be set without CONFIG_NUMA or memory hot-remove
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From: Mel Gorman on 2 Apr 2010 12:10 CONFIG_MIGRATION currently depends on CONFIG_NUMA or on the architecture being able to hot-remove memory. The main users of page migration such as sys_move_pages(), sys_migrate_pages() and cpuset process migration are only beneficial on NUMA so it makes sense. As memory compaction will operate within a zone and is useful on both NUMA and non-NUMA systems, this patch allows CONFIG_MIGRATION to be set if the user selects CONFIG_COMPACTION as an option. Signed-off-by: Mel Gorman <mel(a)csn.ul.ie> Reviewed-by: Christoph Lameter <cl(a)linux-foundation.org> Reviewed-by: Rik van Riel <riel(a)redhat.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu(a)jp.fujitsu.com> --- mm/Kconfig | 18 +++++++++++++++--- 1 files changed, 15 insertions(+), 3 deletions(-) diff --git a/mm/Kconfig b/mm/Kconfig index 9c61158..4fd75a0 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -172,6 +172,16 @@ config SPLIT_PTLOCK_CPUS default "4" # +# support for memory compaction +config COMPACTION + bool "Allow for memory compaction" + def_bool y + select MIGRATION + depends on EXPERIMENTAL && HUGETLBFS && MMU + help + Allows the compaction of memory for the allocation of huge pages. + +# # support for page migration # config MIGRATION @@ -180,9 +190,11 @@ config MIGRATION depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE help Allows the migration of the physical location of pages of processes - while the virtual addresses are not changed. This is useful for - example on NUMA systems to put pages nearer to the processors accessing - the page. + while the virtual addresses are not changed. This is useful in + two situations. The first is on NUMA systems to put pages nearer + to the processors accessing. The second is when allocating huge + pages as migration can relocate pages to satisfy a huge page + allocation instead of reclaiming. config PHYS_ADDR_T_64BIT def_bool 64BIT || ARCH_PHYS_ADDR_T_64BIT -- 1.6.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |